Search Results: ex marrying a friend

I've been with my boyfriend for 3 months. I knew he had an ex- girlfriend who he was with for over 5 years in the beginning already - it came out while we're talking one day and it sounded like his ex-girlfriend broke up with him because he didn't want to get married but she did (they are both in their 40s). I don't know when they broke up or any other details because I am the type of person who don't ask about past relationships.
I recently saw that he has some videos of him and his ex on his phone (from last year when they're on vacation). Yet, I didn't see the few pictures which we've taken in the beginning of our relationship - there are other pictures and videos that he has taken elsewhere though. I don't feel good about that, but I don't know if I should worry about it.
From the very limited information I have, it sounded like they didn't really have any problems other than him not wanting to get married. In the beginning of our relationship, he's already mentioned how people kept asking him about getting married but no one who he's been with made him want to get married yet; he didn't want kids and that he isn't in a hurry to get married because it would happen when he meets the right person. I'm perfectly fine with it because I'm the same way. He said he's been paying attention to me for two months and that he knew he had to talk with me because I was the one. A month into the relationship, he asked if I was going to marry him - he was shocked himself too saying he couldn't believe he just proposed. He started calling me with his last name, his wife, and mama, and saying how we're going to have a son. I thought they're just things he says to people whom he sees, but he said he has never called anyone "mama" - it just came out as if we're already married and has a family. We see each other often and he's been very nice. He told his friends and family about me. I'm telling myself not to worry about the videos of his ex, but it bothers me a little. Thoughts?